The present application refers to an improved frame used to support pull-out and rotating racks, such as the ones commonly used in modern modular kitchen cabinets to support a series of shelves or baskets for food storage purposes.
A frame for racks of this type is disclosed in the Italian application for utility model MC 2004 U000004 filed by the same applicant.
The said application discloses a frame used to support racks that slide and rotate around a vertical axis, composed of a bearing rectangular structure formed of two uprights connected by two crosspieces, namely an upper and a lower crosspiece, respectively coupled to the sliding rod of two telescopic guides mounted on the bottom and top of the cabinet where the rack is to be contained.
The crosspieces are fixed to the sliding rods by means of vertical coaxial pins that allow the rack to rotate with respect to the sliding rods, which in turn allow the rack to be pulled out of the cabinet, whose door is mostly of translating, and not rotating, type, being normally frontally fixed to the front upright. By grabbing and pulling the door, the rack can be extracted and rotated by 90° to move the door laterally and give access to the shelves that are positioned laterally with respect to the user standing in front of the cabinet.
At least one of the crosspieces in the frame of the rack, preferably the lower crosspiece, is connected with the relevant telescopic guide by means of a special cover, which is fixed to the sliding rod of the guide in such a way that the cover only makes rectilinear alternate travels together with the sliding rod of the telescopic guides, while the rack is free to rotate with respect to the said cover.
In fact, the cover acts as support for the mechanisms used to guarantee the correct, safe movement of the rack.
More precisely, the said mechanisms are designed to prevent the rack from travelling backwards into the cabinet, until it is rotated leftwards o rightwards. The backward travel must be prevented until the frame of the rack resumes the initial pull-out position, when the crosspieces are perfectly parallel to the sliding rod of the telescopic guides.
To facilitate and accelerate perfect re-alignment between the crosspieces of the rack and the telescopic guides, the cover is provided with stops attached to corresponding snap-in means mounted on the crosspieces of the rack. This automatically determines the self-centring of the rack with respect to the telescopic guides when the user rotates the rack to place it in the correct position before pushing it inside the cabinet, after picking or storing the desired items.
Some problems have been encountered during the installation and use of the said kitchen cabinets equipped with the above pull-out and rotating racks of known type, and the present invention is intended to provide a solution to these problems.
The first problem consists in the fact that, when pulling-out the rack, the rack can accidentally rotate before the forward travel is completed, thus making the shelves of the rack touch and rub the sides of the cabinet.
As a matter of fact, the only means that are currently available to prevent this inconvenience are the self-centring means of the rack, which are snap-type means, since they need to be released from the crosspieces of the rack when the rack is pushed into rotation at the end of the pull-out travel.
This means that, if accidental transversal forces cause the rotation of the rack during the pull-out travel, the rack starts rotating as soon as the modest resistance offered by the snap-in self-centring means is overcome.
The second inconvenience occurs during the installation of the rack, when the door must be regulated to perfectly touch the four sides of the cabinet. In such a case, regulation is limited by the fact that the door is fixed directly to the front upright of the bearing rectangular structure, whose crosspieces are directly attached to the sliding rod of the telescopic guides by means of the two vertical coaxial pins that are subject to stress in case of regulation.